Breast pump



FIG. 1 is a perspective view showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side view, the left side being a mirror image thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a perspective view thereof, the broken line showing of the bottle is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a breast pump, as shown and described. 